The Killers shot exclusively for OMM at Olympic Studios in South West London. Photograph: Claudia Janke

Las Vegas, 23 July 2008

Late morning in Henderson, the nice suburban neighbourhood Brandon Flowers calls home, and the Killers frontman is in his kitchen. He is, as is his wont, fretting. He has to leave soon for another day's work at the band's new recording studio. This is in an anonymous Las Vegas industrial space, about a 15-minute drive from where each of the four members of the band live: Flowers, Dave Keuning (the guitarist), Mark Stoermer (bass), Ronnie Vannucci (drums). Battle Born they have called it, following the motto on their state flag, a reference to Nevada joining the Union side during the American Civil War.

'It's exciting to branch out. We were talking about the studio maybe being a business venture, hiring it out,' says Flowers. 'It's been great to go in and not have to worry about who's listening.' As the Killers work on their third album, a record that has to top everything they've done before - otherwise the super-zealous Flowers might as well just give up - privacy is paramount. They recorded its predecessor, 2006's Sam's Town, in a studio inside the Palms Casino Resort, one of Vegas's ritziest joints. 'And it's great not to worry about who's going to pop in because they're gambling and they're a high-roller and they want to see the fucking studio.' As befits a man of religious faith, Flowers doesn't swear much. So when he does you get a real measure of his exasperation. 'Playboy bunnies too!' Family man Flowers didn't like that either. 'There was all craziness at the Palms. So now, definitely we're more productive.'

The Killers are America's oddest successful act: four members who look like they should be in four different groups; working-class kids from heartland America - rather than the cosmopolitan coasts - with a love of flamboyance. Committed lovers of Eighties British pop (as evidenced on their first album, Hot Fuss) turned stadium-rock rabble-rousers who dug Bruce Springsteen and the Wild West on the follow-up, Sam's Town

Alongside their joyous disco and rock anthems sit dark songs about trauma, salvation and death: 'Uncle Jonny' dealt with Flowers's cocaine-crazed relative's conviction that aliens were after his sperm (so he tried to shoot his testicles off); 'Bling (Confession of a King)' told how Flowers's father recanted alcoholism and Catholicism to become a Mormon.

The singer's love of the Morrissey B-side 'Sister I'm a Poet' led to the writing of the band's 'Murder Trilogy' - 'Jenny Was a Friend of Mine', 'Midnight Show' and 'Leave the Bourbon on the Shelf'. Flowers ploughed this macabre route more deeply with 'Where is She?', inspired by the murder of a 14-year-old Scottish girl, Jodi Jones, by her goth boyfriend in 2003. Flowers wrote the song from the viewpoint of the victim's mother, not stopping to think of the upset this might cause.

Oh yes. At 27, Flowers is five years younger than his bandmates and the oddest of them all. Lovely, but odd. Phobic about flying, and about the number 621 (his birthday is 21 June). Like his parents and siblings, a Mormon. A young husband and the father to a 13-month-old son, Ammon. Thoughtful and considerate, but also a control freak. An arch-patriot who doesn't seem sure of his politics. He was once quoted as saying he was 'sympathetic to George Bush' and when I'm with him, he mentions approvingly a recent copy of Newsweek which bore the headline 'What Bush Did Right'. But he recently retracted that earlier quote, saying 'I'm in the middle with my beliefs, like everyone else' and to me he talks enthusiastically about Barack Obama.

And he's ambitious. Flowers wants the Killers' name in big lights, for ever and ever, amen. And he'll put in the micro-managing effort to achieve what it takes.

'Brandon will turn in 14-hour days, day after day after day,' Stuart Price says admiringly. The Reading-born musician and producer (previous bands: Les Rhythmes Digitales, Zoot Woman; previous clients: Madonna, Seal) has become, in some ways, the fifth member of the Killers. He did the 'Thin White Duke' remix of 'Mr Brightside' that the band loved so much. Then, as exploratory recordings, he produced 'Leave the Bourbon on the Shelf' and 'Sweet Talk', which appeared on last November's B-sides-and-more compilation Sawdust. The band had tried and failed to record 'Sweet Talk' for Sam's Town.

Price and the Killers clicked. On his first visit to Price's home studio in London, lifelong Anglophile Flowers noted the pictures of David Bowie and Brian Eno on the wall. 'I knew we'd found our man,' recalls Flowers. Now Price is working with them on the follow-up to Sam's Town and Sawdust, and to Hot Fuss before them. Together those albums have sold 12m copies worldwide, helping make the Killers - as one US magazine had it - America's Best British Band. Quick-paced computer whizz Price, the son of two classical pianists, has proved a great foil for Flowers. 'It's in him like it's in us,' says the singer. 'Brandon's meticulous over things and really works at it,' says the producer. 'He's one of those people where it's in his blood. It's a real admirable quality.'

But in Las Vegas, even 14-hour days aren't enough right now. Flowers, with whom most of the band's songs begin, is agonising over a couple of unfinished numbers.

Actually, right now he's happier talking about clothes. He's the perfect age to be a Nirvana kid but Flowers hated grunge, in part because it was so dowdy, partly 'because it sucked the fun out of things'. His teenage love of British music was heard through a prism of style: Echo & the Bunnymen's trenchcoats, Morrissey's flowers, Bowie's chameleonism, Pet Shop Boys' sartorial wit, Oasis's post-football casual swagger. 'I almost follow the music through fashion.'

Thus the Killers were dandies from day one. They blazed out of Sin City wearing pastel jackets and make-up and eye-watering shirts. As the laconic, slightly spacey Keuning will recall of their first show as a foursome, in a Las Vegas club called the Junkyard in August 2002, 'even then, people were like, "Who do these guys think they are?" Well, anybody can wear a T-shirt and jeans. But this is a show and we want to look good and we want to have fun. I think I had a pink shirt on.' Pause. 'I got rid of that shirt.'

After the British Eighties disco look (and sound) of Hot Fuss, the Killers went native for Sam's Town. It was a record that sounded like widescreen America and it had the boots, bootlace ties and waistcoats to prove it.

'With Sam's Town,' says wisecracking life-and-soul Vannucci, 'I think we had just been on tour [promoting Hot Fuss], visiting all these new places, being detached from our desert home.' Indeed: before the release of Hot Fuss, Brandon Flowers had never had a passport. 'Being away from family, remembering where you come from, was probably heavy on Brandon's mind,' the drummer continues. 'And one thing just flowed into the next. It was never, "OK guys, let's dress up like fucking cowboys!"' Vannucci thinks that look might have started with the Anton Corbijnshoot for the album sleeve with the photographer 'playing dressing up...' But, he insists, this was not post-Joshua Tree-style affectation. 'Vegas is not about the Palms Hotel casino and black shiny shirts. If you're local, it's more about horseshit and gunsmoke! So that's what we brought to the stage.' And, in the drummer's case, an extravagant My Name is Wyatt Earp moustache.

Anyway, Flowers wants to underscore this: that look, and that sound, they're all in the past. The Killers as extras from Deadwood? It's so 2007. For album proper number three, the band are going wilder still. 'Sam's Town was very specific. It was a return home album,' says the quiet Stoermer, a former medical student with whom still waters run very deep. 'This new album is perhaps more progressive and... I don't want to say global, but it's more universal.'

On the Killers' new album, to be called Day and Age, there are synths involved. There are big rousing tunes, for sure. But there are also harpsichords, moonscapes, saxophones, brass, strings, feathers and fur and steel drums. Steel drums?

'Seriously, the last time I heard steel drums was in The Little Mermaid!' Flowers exclaims. 'I don't know if that's a good reason or not to use them.'

Fifteen minutes after they come offstage at the Academy in the Irish capital, the Killers' small and busy dressing room under the stairs is sweltering.

Ronnie Vannucci is forced to stand in the corridor outside to talk to Jack Black. The actor-cum-comedy-rocker's band Tenacious D are in town to support Metallica at Marlay Park. Vannucci and Black are guffawing about the perennial rock star problem of overly sweaty gussets. Brandon Flowers, still wired and still perspiring from the performance, sits on a chair, both knees doing the St Vitus Dance. He's digging into a full size box of bran flakes, shovelling the dry cereal into his mouth but taking care to avoid the raisins. Mark Stoermer idly fingers a leather case containing champagne and Guinness. It's a gift from Dublin's favourite sons, and the band the Killers most want to emulate. A card inside reads: 'Welcome to Dublin from The U2'ers'. Their manager, Paul McGuinness, stands by the doorway, chatting. 'He owns the space around him,' Flowers will later chuckle. 'Makes our manager nervous!'

Flowers, too, is a little nervous. Tonight's 850-capacity club show, a warm-up for tomorrow night's show at Marlay Park, which is itself a warm-up for headline slots at the Reading and Leeds festivals, was great. The band played a quasi-acoustic version of 'Smile Like You Mean It', with Flowers at the piano. Their decidedly strange collaboration with Lou Reed, last year's 'Tranquilize' single, worked well. Two new songs, 'Neon Tiger' and 'Spaceman', were greeted enthusiastically by the crowd. But Flowers's racing brain is already on to the next hurdle. Chatting to McGuinness, he discovers that U2's new album is scheduled for release a week before theirs. How do they follow that? 'So there's U2, Oasis, Snow Patrol, Keane, Kaiser Chiefs...' He ticks off the autumn's big albums on his fingers (the U2 record later shifts to next year). Shit. Lot of competition. Flowers chomps at his cereal with agitated gusto.

You might say they haven't made things easy for themselves. The Killers interrupted recording on Day and Age to embark on a month-long tour: a handful of small North American shows followed by this run of European festival dates. Then they are heading to London to hook up with Stuart Price again and finish the album. Everything is running impossibly close to deadline.

After midnight the Killers leave the club and drive the few hundred yards back to their hotel. Flowers's wife Tana and infant son are upstairs but he lingers in the lobby with a laptop, poring over new band photographs till 1am. Some feature the four-piece seemingly standing on the moon. In others, Flowers is wearing a Dolce & Gabbana jacket with elaborate fur and feather epaulettes designed by British fashionista Fee Doran. She was introduced to Flowers by Stuart Price, for whom she once made a black leather catsuit. She's most famous for making the white hooded jumpsuit Kylie Minogue wore in the 'Can't Get You Out of My Head' video.

'Sci-fi jungle!' says Vannucci, jokingly, of the new look that the band - well, the more outré Flowers and Keuning - will be rocking. 'It's the new emo! No longer neo-synth fetishists, we're sci-fi jungle! No more Wyatt Earp moustache, although I could grow it back in a few hours...'

The next day Flowers and I sit down with tea and cookies in the deserted hotel restaurant. Last night, once he got over his collywobbles about the U2 album, he seemed friendly and relaxed but today, talking about the new album properly for the first time, there are nerves.

I say to Flowers: you said that Sam's Town was about embracing more of your own culture. Did you achieve that?

'Well, what's goofy is, America didn't care! Over here in the UK they did. It's sitting alongside Hot Fuss [in sales]. But in America it did half of what Hot Fuss did - 1.5m rather than 3m. So it just shows you how cynical people can be. We were trying to do something heartfelt - and it was heartfelt.'

How did an avowedly American record fail to sell well in America?

'It was kind of cursed from the start. The press were really rough on it.' The Killers were particularly aggrieved with a two-out-of-five review in Rolling Stone. 'I mean, just for having 'When You Were Young' on it, it deserves better than what it got. That song will be around for ever.'

Did Americans think you were trying too hard to be Americans?

'Maybe. We came out with Hot Fuss and were wearing suits and there's make-up and there's glitz. Definitely they saw [the Sam's Town look] as being contrived. I absolutely understand that now when I look at it. It's a never-ending battle for me. We were these poor kids and the whole idea of being a band was to put ourselves out there as this glamorous thing. Almost the opposite of the Strokes - these wealthy kids who are these dirty rock'n'rollers. Instead of dirtying it up, it was about excess and overindulgence and names and Gucci. It's almost a hip hop thing. Bling, that's kinda what it was like.'

Improbable as it may seem, the none-more-vanilla Flowers is hip hop in other ways - shooting his mouth off, proclaiming his own greatness while panning others. It's not the Killers' fault that Sam's Town didn't sell as well as Hot Fuss at home - it was 'cynical' America which didn't 'get' the album. He's open in his desire for the Killers to be a stadium-sized act, to catch up with Coldplay and join up with U2 on the top 'pedestal... They're getting old. You know there's going to be a coupla songs on [U2's new] record you're just going to love. They're unbelievable. But there's gotta be... I dunno, it feels like it's time.'

Last time we spoke he accused Thom Yorke of wasting his talent by not writing such catchy tunes any more. He laid into Green Day for un-American activity: recording a concert DVD in Milton Keynes ('I just thought it was really cheap. To go to a place like England and sing American Idiot...'). Now, he admits ruefully, 'that didn't help us out either [in America]. People love Green Day. Anyone that maybe would have been on the fence with us, that was a real decider that they didn't like us.' Flowers regrets the diss, then, but mainly because it hit his own band's sales.

According to the man who made it, meanwhile, Sam's Town was directly influenced by Springsteen and was one of the best albums of the past 20 years. These vainglorious quotes are still following the Killers round now.

'Yeah, he shouldn't have said any of that crap!' says Keuning with a snort. 'I hadn't thought about Springsteen once... Now he's probably a little bit more careful. I didn't agree with the things he said. Those things don't necessarily represent the band. He was just excited about Sam's Town when he said that 20 years thing, but I had no idea how bad it was going to bite us in the ass.'

'The thing I love about Brandon is that he says whatever the fuck he thinks,' says Price. 'And he doesn't care if he's blowing six litres of smoke up his own arse or in someone else's face. That is so refreshing, to have someone that just goes: "Fuck it, I want to be the best and this is what I think." And he backs that up with hard work.'

He's a funny bloke, Brandon. He has a heart of gold, is thoroughly likable and is staggeringly charismatic on stage. He can write pop hits and stadium anthems seemingly at will. But he's also supremely jittery, occasionally paranoid and easily rattled. It's like he always has something to prove - a legacy, perhaps, of being the baby of his family. He's the youngest of six; his nearest sibling, Shane, is 12 years older than him. It's handsome, born-on-the-4th-of-July Shane (as mentioned in the lyrics to 'Sam's Town') whom young Brandon was always trying to catch up with.

All this can make him come over as aloof and distant. His interview posture is bolt upright like a schoolboy, or arms firmly folded like a shield. It all helps lead to statements of intent that read terribly baldly in print.

Why do you think many people have a problem with your ambition?

'I don't know. I guess they like it better if you just keep your head down and all that. I'm not sure what bothers them so much about it.'

Because they see you as a craven careerist?

'I've seen that before. The singer of Idlewild said I was like Pete Sampras. He could see it in my eyes - dead, cold, a drive, ready to step on whoever I need to. And I'm not like that at all.'

Anyway, golf is your game.

[Grinning] 'Yeah. Tiger Woods, please. But it's just about the songs.'

It's excitement rather than a rampant ego that propels you to talk up your records?

'Yes. That's it. I've never been able to explain it easily. I don't wake up and say, "I'm the greatest."'

That night the Killers play Marlay Park to a sold-out crowd of 32,000, the biggest audience they've ever drawn on their own (that is, other than when they've played at festivals). There is satisfaction within the Killers camp that Metallica didn't sell out the previous night. The 16-song set is blisteringly good. The by-now-traditional set-closing encore is the glorious 'All These Things That I've Done', Flowers's song about struggling to reconcile his Mormon faith with the temptations facing a man and a rock star. As Killers crowds always do, the entire park begins singing the chorus while the band are offstage, readying for the encore: 'I've got soul but I'm not a soldier...' It's spine-tingling to hear.

Throughout the show a member of the Killers' entourage takes pictures from the side of the stage. These days he is the only photographer allowed to shoot the band live. After gigs, the media are invited to pick shots that the band have selected to put up on a special website. Later I ask Flowers why such an edict is necessary.

'Ah-ha-ha,' he laughs nervously. He begins by saying that the ban on outside photographers was in response to publications tending to use the same kind of image repeatedly: him with his mouth wide open, singing. Or, as he puts it, 'the screaming moment... It just to got to be - well, for me, I didn't like it.'

And is it correct that you'll only be filmed head-on, not from underneath?

'Yeah. Why? It's a very unflattering place to have your picture taken. You can't avoid looking like you have a double chin, especially if you're singing and opening your mouth and screaming. It's a misrepresentation.'

But you're lean and in good shape.

'I'm lean. But I'm not as lean as the dreams of.... Iggy Pop and the good old days.'

Would you say you were vain, Brandon?

[Laughing] 'I don't know if it means I'm vain. I'm cautious!'

And you like being in control?

'Well, you know, it's our destiny that we're playing with here.'

Presumably you appreciate that your banning photographers from your shows will be construed as controlling and egomaniacal?

'Yeah, I don't understand that. I don't mind it. People can think what they want to think.'

London, 3 September

Last night the Killers partied. Brandon Flowers collected the award for Most Stylish Man at GQ's Men of the Year event at the Royal Opera House. He smoked cigarettes and drank champagne and ended the night at celeb hang-out Bungalow 8. He's a practising Mormon but not 100 per cent observant, although his son is named after a prophet in the Book of Mormon. How has having a child affected his faith?

'It's kind of solidified it.' He pauses, wary of discussing religion - he's enough of a student of music history to know that the holy rock'n'roller is a precarious route to go down. 'I feel like it's an arrogant thought to think we're an accident, or that we're this smart without a little bit of a help. I just think it's a miracle.'

For some people, childbirth reaffirms their faith in creationism; a higher power had a hand...

'Yeah, definitely. It's definitely made me... And it's made me a lot less selfish too, so it's good. I love music, but I look at it more as my job now than I did. Now I'm going off to work. Now I almost think I'm doing this for him and for his future. Everything's changed. There's all kinds of shit brewing in my brain. I wonder if it's weird that I get manicures! Ha ha ha! My dad didn't get manicures, I don't know if I should... Why do I? I dunno! Because they give you a massage at the end of it. It feels nice.'

We're talking in Olympic Studios in Barnes, south-west London. The Killers have two-and-a-half days to finish Day and Age. The tight schedule has meant they had to nix yesterday's planned recording session with Elton John: he and Flowers have written a Christmas song (the Killers' third), called 'Joseph, Better You Than Me'.

The band play me a handful of new songs. 'Human', the first single, is a Pet Shop Boys-style synth-pop zoomer that should please fans of 'Mr Brightside'. 'Losing Touch' is driven by blasts of dirty saxophone. 'I Can't Stay' is brilliantly wonky: steel drums, harpsichords and a shuffling rhythm which Keuning describes as 'stranded on an island', and which Flowers admits was taken from Unit 4+2's 1965 British No 1 'Concrete and Clay' (he heard it on the soundtrack to Rushmore). And on the 'Club Tropicana'-esque 'Joyride', the Killers got the funk.

On one listen it's thrilling, the sound of America's most adventurous big-hitters spinning off in umpteen new directions. As Stuart Price says: 'I think the wrongness is part of the thing that appeals to Europeans about the Killers.'

'A Dustland Fairytale' is more reminiscent of the grand rock of Sam's Town. Studded with punchy piano, it sounds like a Jim Steinman production. It features lines like 'slick chrome American prince', 'long brown hair and foolish eyes', and 'white trash county'. It's the story of how Flowers's mum and dad met - they were both aged 15 and lived on the same trailer park.

The song that's causing Flowers most trouble is 'Goodnight, Travel Well'. Set to be the album's closer and running to almost seven minutes, it's a tribute to Dave Keuning's recently deceased mother, and to Brandon Flowers's mum, who has a brain tumour (he says she's responding 'really well to the chemo and the radiation so far'). He needs to get the lyrics right: tender but not mawkish. I hear the unfinished version. It's a gothic symphony, bursting with brass and strings.

As Flowers describes it: 'It goes from being the darkest thing we've ever done before shooting up to the clouds at the end. Oh, it's a heartbreaker. It just rips your guts out.'

If Flowers can face singing it night after night, it should be a great main set closer.

'We use the analogy of too much chocolate. That's maybe how Killers shows have been in the past, sometimes it's too much - we don't have our ups and downs. It's been a real breath of fresh air doing the songs from Sawdust and the stripped down 'Smile Like You Mean it'. It's not just in your face the whole time. It really felt like a real band. A more mature...' Flowers stops and smiles. 'Men were up there playing.'

Right then. Studio time. The Killers have a little over 48 hours to nail the finale to the album that, if all goes to plan, will keep them on the road until the end of 2010. The only way is up. In terms of sound and in terms of stature, their ambition knows no bounds. If Brandon Flowers, baby of the family and baby of the band, has anything to do with it, the world's record-buying, concert-going masses will be moved.

'I have an unexplainable drive,' he cheerfully admits. 'I don't know exactly where it comes from, but it borders on obsession. There's something special about bringing that many people together and celebrating that way. I want that! I am greedy and selfish but I want that every night.'

Bigmouth strikes again: Brandon Flowers bitches

'I can see the Strokes play or Franz Ferdinand play and it's real, and I haven't gotten that from the Bravery. I think people will see through them.'March 2005

'We have a song called "Midnight Show" and in America they love it. In England they don't move at all. What's wrong with them?' April 2005

'What song do I hate? I think 'Daughters' by John Mayer would be a good candidate.' 2005

On Fall Out Boy: 'Emo is dangerous. There's a creature inside me that wants to beat all those bands to death.' June 2006

On Thom Yorke: 'He should feel grateful that he's [been] given the gift to write pop songs - which he needs to write again.' September 2006

On Green Day filming their American Idiot DVD in the UK: 'I saw it as a very negative thing towards Americans. It really lit a fire in me.' October 2006

'I think people are lazy, and that goes for making music too.' November 2006